Sometimes, when a friendships gets particularely toxic and there's nothing you can do to help your friend, it's best to break the friendship. Now, this is pretty hard, as the friend will most likely get offended or hurt, so here are some ways to break it:

* Explain - tell them calmly why you're breaking the friendship and make sure to back up your points, for example:

I'm very sorry, but I feel that I can't be friends with you anymore because you could never admit you were wrong. You were always suspicious and you would never believe what I said and just think I was lying.

I did not!

I'm afraid you did, one time you even went as far as telling on me because you thought that because I was laughing, it was directed at you. I didn't do anything wrong, what kind of a friend does that?

* Do it directly - don't text, don't email. If you do that, then it's more cowardly as it's not in person, and your friend might misinterpret things.

* Give them tips - even if they won't work, they could still be helpful in the future (if your friend takes it in!). For example:

However, I'm sure you can be a great friend in future. When you're finding a friend it's best to be open-minded and not get suspicious if they act differently. Just because they're acting different doesn't mean it's because of you.

* Stay civil - if you encounter that friend again don't be rude, just stay calm and polite, which is no reason to get upset over!

I hope this might help you as I know that breaking a friendship is hard.

:)